#IWantToHelp - Anycubic Photon Firmware <-> Chitubox slicer setting correlation experiment

[berkakinci]

#IWantToHelp

I ran an experiment to correlate Chitubox (v1.7.0) slicer settings with Anycubic Photon Firmware (4.2.19.3) behavior. I thought I'd share the results for others' benefit. Please insert the below in the repo in a place that makes sense to you.

Anycubic Photon Firmware <-> Chitubox slicer setting correlation experiment

I was scratching my head about what exactly the "settings" changed. I couldn't find satisfactory answers online, so I had to do an experiment.

###Method:
In Chitubox: put a model far off the build plate. Model is off the plate because I had resin in the vat, so I did't want it curing.
Make a bunch of .photon files with different combinations of settings; with file names like "E_50,2,2,5,0,0 15,10,65,65,150.photon"
Record video of running the first few layers of each file and go back and try to make sense of stuff.

###Results:
I'll try to list what I found, but first, the "anatomy" of a layer print on the Anycubic Photon. These are "instantaneous time points" I'll use later:

1. Start Layer exposure
2. Finish Layer exposure
3. Start move slowly away from screen
4. Start move quickly away from screen
5. Start move quickly back toward screen
6. Arrive at next layer Z
7. Start Layer+1 exposure

Here is the settings screenshot for the file "E_50,2,2,5,0,0 15,10,65,65,150.photon":

I hope the "bottom" layer stuff is self explanatory; it's just special set of parameters for the first few (2 in this picture) layers. I didn't scrutinize the transition between bottom to normal layers.
One exception: "Bottom Light-off Delay" doesn't seem to do anything.

Here are the more difficult-to-understand (IMO) settings:

• Light-off Delay: This is the time between time-points t2 and t7 above.
• Lift(ing) Distance: This is the total Z distance traveled away from the screen between layers. It's traveled between time-points t3 to t5.
• Lift(ing) Speed: This is the Z speed between time-points t3 and t4.
• Retract Speed: This is the Z speed between time-points t4 and t6.

​Now I see the biggest source of my confusion: There is no setting for the distance traveled between time-points t3 and t4. It seems "hardcoded" at 2.5mm (my estimate).
​
I was messing with these settings because I can clearly hear the layer doesn't separate from FEP film in those 2.5mm. Now I see why my messing was in vain. I suspect there are M8xxxx gcodes for that distance. I'll start looking in Photonsters repo.